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900 lines
32 KiB
Ruby
900 lines
32 KiB
Ruby
# frozen_string_literal: true
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module ActiveRecord
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# = Active Record \Relation
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class Relation
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MULTI_VALUE_METHODS = [:includes, :eager_load, :preload, :select, :group,
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:order, :joins, :left_outer_joins, :references,
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:extending, :unscope, :optimizer_hints, :annotate]
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SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :reordering, :strict_loading,
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:reverse_order, :distinct, :create_with, :skip_query_cache]
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CLAUSE_METHODS = [:where, :having, :from]
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INVALID_METHODS_FOR_DELETE_ALL = [:distinct, :group, :having]
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VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS + CLAUSE_METHODS
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include Enumerable
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include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
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attr_reader :table, :klass, :loaded, :predicate_builder
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attr_accessor :skip_preloading_value
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alias :model :klass
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alias :loaded? :loaded
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alias :locked? :lock_value
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def initialize(klass, table: klass.arel_table, predicate_builder: klass.predicate_builder, values: {})
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@klass = klass
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@table = table
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@values = values
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@loaded = false
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@predicate_builder = predicate_builder
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@delegate_to_klass = false
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end
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def initialize_copy(other)
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@values = @values.dup
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reset
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end
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def arel_attribute(name) # :nodoc:
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table[name]
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end
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deprecate :arel_attribute
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def bind_attribute(name, value) # :nodoc:
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if reflection = klass._reflect_on_association(name)
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name = reflection.foreign_key
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value = value.read_attribute(reflection.klass.primary_key) unless value.nil?
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end
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attr = table[name]
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bind = predicate_builder.build_bind_attribute(attr.name, value)
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yield attr, bind
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end
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# Initializes new record from relation while maintaining the current
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# scope.
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#
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# Expects arguments in the same format as {ActiveRecord::Base.new}[rdoc-ref:Core.new].
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#
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# users = User.where(name: 'DHH')
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# user = users.new # => #<User id: nil, name: "DHH", created_at: nil, updated_at: nil>
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#
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# You can also pass a block to new with the new record as argument:
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#
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# user = users.new { |user| user.name = 'Oscar' }
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# user.name # => Oscar
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def new(attributes = nil, &block)
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block = current_scope_restoring_block(&block)
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scoping { _new(attributes, &block) }
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end
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alias build new
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# Tries to create a new record with the same scoped attributes
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# defined in the relation. Returns the initialized object if validation fails.
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#
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# Expects arguments in the same format as
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# {ActiveRecord::Base.create}[rdoc-ref:Persistence::ClassMethods#create].
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#
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# ==== Examples
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#
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# users = User.where(name: 'Oscar')
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# users.create # => #<User id: 3, name: "Oscar", ...>
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#
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# users.create(name: 'fxn')
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# users.create # => #<User id: 4, name: "fxn", ...>
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#
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# users.create { |user| user.name = 'tenderlove' }
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# # => #<User id: 5, name: "tenderlove", ...>
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#
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# users.create(name: nil) # validation on name
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# # => #<User id: nil, name: nil, ...>
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def create(attributes = nil, &block)
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if attributes.is_a?(Array)
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attributes.collect { |attr| create(attr, &block) }
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else
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block = current_scope_restoring_block(&block)
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scoping { _create(attributes, &block) }
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end
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end
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# Similar to #create, but calls
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# {create!}[rdoc-ref:Persistence::ClassMethods#create!]
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# on the base class. Raises an exception if a validation error occurs.
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#
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# Expects arguments in the same format as
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# {ActiveRecord::Base.create!}[rdoc-ref:Persistence::ClassMethods#create!].
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def create!(attributes = nil, &block)
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if attributes.is_a?(Array)
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attributes.collect { |attr| create!(attr, &block) }
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else
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block = current_scope_restoring_block(&block)
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scoping { _create!(attributes, &block) }
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end
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end
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def first_or_create(attributes = nil, &block) # :nodoc:
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first || create(attributes, &block)
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end
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def first_or_create!(attributes = nil, &block) # :nodoc:
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first || create!(attributes, &block)
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end
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def first_or_initialize(attributes = nil, &block) # :nodoc:
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first || new(attributes, &block)
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end
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# Finds the first record with the given attributes, or creates a record
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# with the attributes if one is not found:
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#
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# # Find the first user named "Penélope" or create a new one.
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# User.find_or_create_by(first_name: 'Penélope')
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# # => #<User id: 1, first_name: "Penélope", last_name: nil>
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#
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# # Find the first user named "Penélope" or create a new one.
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# # We already have one so the existing record will be returned.
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# User.find_or_create_by(first_name: 'Penélope')
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# # => #<User id: 1, first_name: "Penélope", last_name: nil>
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#
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# # Find the first user named "Scarlett" or create a new one with
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# # a particular last name.
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# User.create_with(last_name: 'Johansson').find_or_create_by(first_name: 'Scarlett')
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# # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson">
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#
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# This method accepts a block, which is passed down to #create. The last example
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# above can be alternatively written this way:
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#
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# # Find the first user named "Scarlett" or create a new one with a
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# # different last name.
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# User.find_or_create_by(first_name: 'Scarlett') do |user|
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# user.last_name = 'Johansson'
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# end
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# # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson">
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#
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# This method always returns a record, but if creation was attempted and
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# failed due to validation errors it won't be persisted, you get what
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# #create returns in such situation.
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#
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# Please note <b>this method is not atomic</b>, it runs first a SELECT, and if
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# there are no results an INSERT is attempted. If there are other threads
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# or processes there is a race condition between both calls and it could
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# be the case that you end up with two similar records.
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#
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# If this might be a problem for your application, please see #create_or_find_by.
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def find_or_create_by(attributes, &block)
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find_by(attributes) || create(attributes, &block)
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end
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# Like #find_or_create_by, but calls
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# {create!}[rdoc-ref:Persistence::ClassMethods#create!] so an exception
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# is raised if the created record is invalid.
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def find_or_create_by!(attributes, &block)
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find_by(attributes) || create!(attributes, &block)
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end
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# Attempts to create a record with the given attributes in a table that has a unique constraint
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# on one or several of its columns. If a row already exists with one or several of these
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# unique constraints, the exception such an insertion would normally raise is caught,
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# and the existing record with those attributes is found using #find_by!.
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#
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# This is similar to #find_or_create_by, but avoids the problem of stale reads between the SELECT
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# and the INSERT, as that method needs to first query the table, then attempt to insert a row
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# if none is found.
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#
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# There are several drawbacks to #create_or_find_by, though:
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#
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# * The underlying table must have the relevant columns defined with unique constraints.
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# * A unique constraint violation may be triggered by only one, or at least less than all,
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# of the given attributes. This means that the subsequent #find_by! may fail to find a
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# matching record, which will then raise an <tt>ActiveRecord::RecordNotFound</tt> exception,
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# rather than a record with the given attributes.
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# * While we avoid the race condition between SELECT -> INSERT from #find_or_create_by,
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# we actually have another race condition between INSERT -> SELECT, which can be triggered
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# if a DELETE between those two statements is run by another client. But for most applications,
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# that's a significantly less likely condition to hit.
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# * It relies on exception handling to handle control flow, which may be marginally slower.
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# * The primary key may auto-increment on each create, even if it fails. This can accelerate
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# the problem of running out of integers, if the underlying table is still stuck on a primary
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# key of type int (note: All Rails apps since 5.1+ have defaulted to bigint, which is not liable
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# to this problem).
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#
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# This method will return a record if all given attributes are covered by unique constraints
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# (unless the INSERT -> DELETE -> SELECT race condition is triggered), but if creation was attempted
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# and failed due to validation errors it won't be persisted, you get what #create returns in
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# such situation.
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def create_or_find_by(attributes, &block)
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transaction(requires_new: true) { create(attributes, &block) }
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rescue ActiveRecord::RecordNotUnique
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find_by!(attributes)
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end
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# Like #create_or_find_by, but calls
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# {create!}[rdoc-ref:Persistence::ClassMethods#create!] so an exception
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# is raised if the created record is invalid.
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def create_or_find_by!(attributes, &block)
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transaction(requires_new: true) { create!(attributes, &block) }
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rescue ActiveRecord::RecordNotUnique
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find_by!(attributes)
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end
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# Like #find_or_create_by, but calls {new}[rdoc-ref:Core#new]
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# instead of {create}[rdoc-ref:Persistence::ClassMethods#create].
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def find_or_initialize_by(attributes, &block)
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find_by(attributes) || new(attributes, &block)
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end
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# Runs EXPLAIN on the query or queries triggered by this relation and
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# returns the result as a string. The string is formatted imitating the
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# ones printed by the database shell.
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#
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# Note that this method actually runs the queries, since the results of some
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# are needed by the next ones when eager loading is going on.
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#
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# Please see further details in the
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# {Active Record Query Interface guide}[https://guides.rubyonrails.org/active_record_querying.html#running-explain].
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def explain
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exec_explain(collecting_queries_for_explain { exec_queries })
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end
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# Converts relation objects to Array.
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def to_ary
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records.dup
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end
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alias to_a to_ary
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def records # :nodoc:
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load
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@records
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end
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# Serializes the relation objects Array.
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def encode_with(coder)
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coder.represent_seq(nil, records)
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end
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# Returns size of the records.
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def size
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loaded? ? @records.length : count(:all)
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end
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# Returns true if there are no records.
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def empty?
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return @records.empty? if loaded?
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!exists?
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end
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# Returns true if there are no records.
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def none?
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return super if block_given?
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empty?
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end
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# Returns true if there are any records.
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def any?
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return super if block_given?
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!empty?
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end
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# Returns true if there is exactly one record.
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def one?
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return super if block_given?
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limit_value ? records.one? : size == 1
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end
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# Returns true if there is more than one record.
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def many?
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return super if block_given?
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limit_value ? records.many? : size > 1
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end
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# Returns a stable cache key that can be used to identify this query.
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# The cache key is built with a fingerprint of the SQL query.
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#
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# Product.where("name like ?", "%Cosmic Encounter%").cache_key
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# # => "products/query-1850ab3d302391b85b8693e941286659"
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#
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# If ActiveRecord::Base.collection_cache_versioning is turned off, as it was
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# in Rails 6.0 and earlier, the cache key will also include a version.
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#
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# ActiveRecord::Base.collection_cache_versioning = false
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# Product.where("name like ?", "%Cosmic Encounter%").cache_key
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# # => "products/query-1850ab3d302391b85b8693e941286659-1-20150714212553907087000"
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#
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# You can also pass a custom timestamp column to fetch the timestamp of the
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# last updated record.
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#
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# Product.where("name like ?", "%Game%").cache_key(:last_reviewed_at)
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def cache_key(timestamp_column = "updated_at")
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@cache_keys ||= {}
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@cache_keys[timestamp_column] ||= klass.collection_cache_key(self, timestamp_column)
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end
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def compute_cache_key(timestamp_column = :updated_at) # :nodoc:
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query_signature = ActiveSupport::Digest.hexdigest(to_sql)
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key = "#{klass.model_name.cache_key}/query-#{query_signature}"
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if collection_cache_versioning
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key
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else
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"#{key}-#{compute_cache_version(timestamp_column)}"
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end
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end
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private :compute_cache_key
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# Returns a cache version that can be used together with the cache key to form
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# a recyclable caching scheme. The cache version is built with the number of records
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# matching the query, and the timestamp of the last updated record. When a new record
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# comes to match the query, or any of the existing records is updated or deleted,
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# the cache version changes.
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#
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# If the collection is loaded, the method will iterate through the records
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# to generate the timestamp, otherwise it will trigger one SQL query like:
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#
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# SELECT COUNT(*), MAX("products"."updated_at") FROM "products" WHERE (name like '%Cosmic Encounter%')
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def cache_version(timestamp_column = :updated_at)
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if collection_cache_versioning
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@cache_versions ||= {}
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@cache_versions[timestamp_column] ||= compute_cache_version(timestamp_column)
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end
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end
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def compute_cache_version(timestamp_column) # :nodoc:
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timestamp_column = timestamp_column.to_s
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if loaded? || distinct_value
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size = records.size
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if size > 0
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timestamp = records.map { |record| record.read_attribute(timestamp_column) }.max
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end
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else
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collection = eager_loading? ? apply_join_dependency : self
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column = connection.visitor.compile(table[timestamp_column])
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select_values = "COUNT(*) AS #{connection.quote_column_name("size")}, MAX(%s) AS timestamp"
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if collection.has_limit_or_offset?
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query = collection.select("#{column} AS collection_cache_key_timestamp")
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subquery_alias = "subquery_for_cache_key"
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subquery_column = "#{subquery_alias}.collection_cache_key_timestamp"
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arel = query.build_subquery(subquery_alias, select_values % subquery_column)
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else
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query = collection.unscope(:order)
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query.select_values = [select_values % column]
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arel = query.arel
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end
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size, timestamp = connection.select_rows(arel, nil).first
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if size
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column_type = klass.type_for_attribute(timestamp_column)
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timestamp = column_type.deserialize(timestamp)
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else
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size = 0
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end
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end
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if timestamp
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"#{size}-#{timestamp.utc.to_s(cache_timestamp_format)}"
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else
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"#{size}"
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end
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end
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private :compute_cache_version
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# Returns a cache key along with the version.
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def cache_key_with_version
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if version = cache_version
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"#{cache_key}-#{version}"
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else
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cache_key
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end
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end
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# Scope all queries to the current scope.
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#
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# Comment.where(post_id: 1).scoping do
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# Comment.first
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# end
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# # => SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = 1 ORDER BY "comments"."id" ASC LIMIT 1
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#
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# Please check unscoped if you want to remove all previous scopes (including
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# the default_scope) during the execution of a block.
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def scoping
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already_in_scope? ? yield : _scoping(self) { yield }
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end
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def _exec_scope(*args, &block) # :nodoc:
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@delegate_to_klass = true
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_scoping(nil) { instance_exec(*args, &block) || self }
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ensure
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@delegate_to_klass = false
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end
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# Updates all records in the current relation with details given. This method constructs a single SQL UPDATE
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# statement and sends it straight to the database. It does not instantiate the involved models and it does not
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# trigger Active Record callbacks or validations. However, values passed to #update_all will still go through
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# Active Record's normal type casting and serialization. Returns the number of rows affected.
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#
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# Note: As Active Record callbacks are not triggered, this method will not automatically update +updated_at+/+updated_on+ columns.
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#
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# ==== Parameters
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#
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# * +updates+ - A string, array, or hash representing the SET part of an SQL statement.
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#
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# ==== Examples
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#
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# # Update all customers with the given attributes
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# Customer.update_all wants_email: true
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#
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# # Update all books with 'Rails' in their title
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# Book.where('title LIKE ?', '%Rails%').update_all(author: 'David')
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#
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# # Update all books that match conditions, but limit it to 5 ordered by date
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# Book.where('title LIKE ?', '%Rails%').order(:created_at).limit(5).update_all(author: 'David')
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#
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# # Update all invoices and set the number column to its id value.
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# Invoice.update_all('number = id')
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def update_all(updates)
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raise ArgumentError, "Empty list of attributes to change" if updates.blank?
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if eager_loading?
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relation = apply_join_dependency
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return relation.update_all(updates)
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end
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stmt = Arel::UpdateManager.new
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stmt.table(arel.join_sources.empty? ? table : arel.source)
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stmt.key = table[primary_key]
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stmt.take(arel.limit)
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stmt.offset(arel.offset)
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stmt.order(*arel.orders)
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stmt.wheres = arel.constraints
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if updates.is_a?(Hash)
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if klass.locking_enabled? &&
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!updates.key?(klass.locking_column) &&
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!updates.key?(klass.locking_column.to_sym)
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attr = table[klass.locking_column]
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updates[attr.name] = _increment_attribute(attr)
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end
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stmt.set _substitute_values(updates)
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else
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stmt.set Arel.sql(klass.sanitize_sql_for_assignment(updates, table.name))
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end
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@klass.connection.update stmt, "#{@klass} Update All"
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end
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def update(id = :all, attributes) # :nodoc:
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if id == :all
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|
each { |record| record.update(attributes) }
|
|
else
|
|
klass.update(id, attributes)
|
|
end
|
|
end
|
|
|
|
# Updates the counters of the records in the current relation.
|
|
#
|
|
# ==== Parameters
|
|
#
|
|
# * +counter+ - A Hash containing the names of the fields to update as keys and the amount to update as values.
|
|
# * <tt>:touch</tt> option - Touch the timestamp columns when updating.
|
|
# * If attributes names are passed, they are updated along with update_at/on attributes.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# # For Posts by a given author increment the comment_count by 1.
|
|
# Post.where(author_id: author.id).update_counters(comment_count: 1)
|
|
def update_counters(counters)
|
|
touch = counters.delete(:touch)
|
|
|
|
updates = {}
|
|
counters.each do |counter_name, value|
|
|
attr = table[counter_name]
|
|
updates[attr.name] = _increment_attribute(attr, value)
|
|
end
|
|
|
|
if touch
|
|
names = touch if touch != true
|
|
names = Array.wrap(names)
|
|
options = names.extract_options!
|
|
touch_updates = klass.touch_attributes_with_time(*names, **options)
|
|
updates.merge!(touch_updates) unless touch_updates.empty?
|
|
end
|
|
|
|
update_all updates
|
|
end
|
|
|
|
# Touches all records in the current relation, setting the +updated_at+/+updated_on+ attributes to the current time or the time specified.
|
|
# It does not instantiate the involved models, and it does not trigger Active Record callbacks or validations.
|
|
# This method can be passed attribute names and an optional time argument.
|
|
# If attribute names are passed, they are updated along with +updated_at+/+updated_on+ attributes.
|
|
# If no time argument is passed, the current time is used as default.
|
|
#
|
|
# === Examples
|
|
#
|
|
# # Touch all records
|
|
# Person.all.touch_all
|
|
# # => "UPDATE \"people\" SET \"updated_at\" = '2018-01-04 22:55:23.132670'"
|
|
#
|
|
# # Touch multiple records with a custom attribute
|
|
# Person.all.touch_all(:created_at)
|
|
# # => "UPDATE \"people\" SET \"updated_at\" = '2018-01-04 22:55:23.132670', \"created_at\" = '2018-01-04 22:55:23.132670'"
|
|
#
|
|
# # Touch multiple records with a specified time
|
|
# Person.all.touch_all(time: Time.new(2020, 5, 16, 0, 0, 0))
|
|
# # => "UPDATE \"people\" SET \"updated_at\" = '2020-05-16 00:00:00'"
|
|
#
|
|
# # Touch records with scope
|
|
# Person.where(name: 'David').touch_all
|
|
# # => "UPDATE \"people\" SET \"updated_at\" = '2018-01-04 22:55:23.132670' WHERE \"people\".\"name\" = 'David'"
|
|
def touch_all(*names, time: nil)
|
|
update_all klass.touch_attributes_with_time(*names, time: time)
|
|
end
|
|
|
|
# Destroys the records by instantiating each
|
|
# record and calling its {#destroy}[rdoc-ref:Persistence#destroy] method.
|
|
# Each object's callbacks are executed (including <tt>:dependent</tt> association options).
|
|
# Returns the collection of objects that were destroyed; each will be frozen, to
|
|
# reflect that no changes should be made (since they can't be persisted).
|
|
#
|
|
# Note: Instantiation, callback execution, and deletion of each
|
|
# record can be time consuming when you're removing many records at
|
|
# once. It generates at least one SQL +DELETE+ query per record (or
|
|
# possibly more, to enforce your callbacks). If you want to delete many
|
|
# rows quickly, without concern for their associations or callbacks, use
|
|
# #delete_all instead.
|
|
#
|
|
# ==== Examples
|
|
#
|
|
# Person.where(age: 0..18).destroy_all
|
|
def destroy_all
|
|
records.each(&:destroy).tap { reset }
|
|
end
|
|
|
|
# Deletes the records without instantiating the records
|
|
# first, and hence not calling the {#destroy}[rdoc-ref:Persistence#destroy]
|
|
# method nor invoking callbacks.
|
|
# This is a single SQL DELETE statement that goes straight to the database, much more
|
|
# efficient than #destroy_all. Be careful with relations though, in particular
|
|
# <tt>:dependent</tt> rules defined on associations are not honored. Returns the
|
|
# number of rows affected.
|
|
#
|
|
# Post.where(person_id: 5).where(category: ['Something', 'Else']).delete_all
|
|
#
|
|
# Both calls delete the affected posts all at once with a single DELETE statement.
|
|
# If you need to destroy dependent associations or call your <tt>before_*</tt> or
|
|
# +after_destroy+ callbacks, use the #destroy_all method instead.
|
|
#
|
|
# If an invalid method is supplied, #delete_all raises an ActiveRecordError:
|
|
#
|
|
# Post.distinct.delete_all
|
|
# # => ActiveRecord::ActiveRecordError: delete_all doesn't support distinct
|
|
def delete_all
|
|
invalid_methods = INVALID_METHODS_FOR_DELETE_ALL.select do |method|
|
|
value = @values[method]
|
|
method == :distinct ? value : value&.any?
|
|
end
|
|
if invalid_methods.any?
|
|
raise ActiveRecordError.new("delete_all doesn't support #{invalid_methods.join(', ')}")
|
|
end
|
|
|
|
if eager_loading?
|
|
relation = apply_join_dependency
|
|
return relation.delete_all
|
|
end
|
|
|
|
stmt = Arel::DeleteManager.new
|
|
stmt.from(arel.join_sources.empty? ? table : arel.source)
|
|
stmt.key = table[primary_key]
|
|
stmt.take(arel.limit)
|
|
stmt.offset(arel.offset)
|
|
stmt.order(*arel.orders)
|
|
stmt.wheres = arel.constraints
|
|
|
|
affected = @klass.connection.delete(stmt, "#{@klass} Destroy")
|
|
|
|
reset
|
|
affected
|
|
end
|
|
|
|
# Finds and destroys all records matching the specified conditions.
|
|
# This is short-hand for <tt>relation.where(condition).destroy_all</tt>.
|
|
# Returns the collection of objects that were destroyed.
|
|
#
|
|
# If no record is found, returns empty array.
|
|
#
|
|
# Person.destroy_by(id: 13)
|
|
# Person.destroy_by(name: 'Spartacus', rating: 4)
|
|
# Person.destroy_by("published_at < ?", 2.weeks.ago)
|
|
def destroy_by(*args)
|
|
where(*args).destroy_all
|
|
end
|
|
|
|
# Finds and deletes all records matching the specified conditions.
|
|
# This is short-hand for <tt>relation.where(condition).delete_all</tt>.
|
|
# Returns the number of rows affected.
|
|
#
|
|
# If no record is found, returns <tt>0</tt> as zero rows were affected.
|
|
#
|
|
# Person.delete_by(id: 13)
|
|
# Person.delete_by(name: 'Spartacus', rating: 4)
|
|
# Person.delete_by("published_at < ?", 2.weeks.ago)
|
|
def delete_by(*args)
|
|
where(*args).delete_all
|
|
end
|
|
|
|
# Causes the records to be loaded from the database if they have not
|
|
# been loaded already. You can use this if for some reason you need
|
|
# to explicitly load some records before actually using them. The
|
|
# return value is the relation itself, not the records.
|
|
#
|
|
# Post.where(published: true).load # => #<ActiveRecord::Relation>
|
|
def load(&block)
|
|
unless loaded?
|
|
@records = exec_queries(&block)
|
|
@loaded = true
|
|
end
|
|
|
|
self
|
|
end
|
|
|
|
# Forces reloading of relation.
|
|
def reload
|
|
reset
|
|
load
|
|
end
|
|
|
|
def reset
|
|
@delegate_to_klass = false
|
|
@to_sql = @arel = @loaded = @should_eager_load = nil
|
|
@offsets = @take = nil
|
|
@records = [].freeze
|
|
self
|
|
end
|
|
|
|
# Returns sql statement for the relation.
|
|
#
|
|
# User.where(name: 'Oscar').to_sql
|
|
# # => SELECT "users".* FROM "users" WHERE "users"."name" = 'Oscar'
|
|
def to_sql
|
|
@to_sql ||= begin
|
|
if eager_loading?
|
|
apply_join_dependency do |relation, join_dependency|
|
|
relation = join_dependency.apply_column_aliases(relation)
|
|
relation.to_sql
|
|
end
|
|
else
|
|
conn = klass.connection
|
|
conn.unprepared_statement { conn.to_sql(arel) }
|
|
end
|
|
end
|
|
end
|
|
|
|
# Returns a hash of where conditions.
|
|
#
|
|
# User.where(name: 'Oscar').where_values_hash
|
|
# # => {name: "Oscar"}
|
|
def where_values_hash(relation_table_name = klass.table_name)
|
|
where_clause.to_h(relation_table_name)
|
|
end
|
|
|
|
def scope_for_create
|
|
hash = where_values_hash
|
|
hash.delete(klass.inheritance_column) if klass.finder_needs_type_condition?
|
|
create_with_value.each { |k, v| hash[k.to_s] = v } unless create_with_value.empty?
|
|
hash
|
|
end
|
|
|
|
# Returns true if relation needs eager loading.
|
|
def eager_loading?
|
|
@should_eager_load ||=
|
|
eager_load_values.any? ||
|
|
includes_values.any? && (joined_includes_values.any? || references_eager_loaded_tables?)
|
|
end
|
|
|
|
# Joins that are also marked for preloading. In which case we should just eager load them.
|
|
# Note that this is a naive implementation because we could have strings and symbols which
|
|
# represent the same association, but that aren't matched by this. Also, we could have
|
|
# nested hashes which partially match, e.g. { a: :b } & { a: [:b, :c] }
|
|
def joined_includes_values
|
|
includes_values & joins_values
|
|
end
|
|
|
|
# Compares two relations for equality.
|
|
def ==(other)
|
|
case other
|
|
when Associations::CollectionProxy, AssociationRelation
|
|
self == other.records
|
|
when Relation
|
|
other.to_sql == to_sql
|
|
when Array
|
|
records == other
|
|
end
|
|
end
|
|
|
|
def pretty_print(q)
|
|
q.pp(records)
|
|
end
|
|
|
|
# Returns true if relation is blank.
|
|
def blank?
|
|
records.blank?
|
|
end
|
|
|
|
def values
|
|
@values.dup
|
|
end
|
|
|
|
def inspect
|
|
subject = loaded? ? records : annotate("loading for inspect")
|
|
entries = subject.take([limit_value, 11].compact.min).map!(&:inspect)
|
|
|
|
entries[10] = "..." if entries.size == 11
|
|
|
|
"#<#{self.class.name} [#{entries.join(', ')}]>"
|
|
end
|
|
|
|
def empty_scope? # :nodoc:
|
|
@values == klass.unscoped.values
|
|
end
|
|
|
|
def has_limit_or_offset? # :nodoc:
|
|
limit_value || offset_value
|
|
end
|
|
|
|
def alias_tracker(joins = [], aliases = nil) # :nodoc:
|
|
ActiveRecord::Associations::AliasTracker.create(connection, table.name, joins, aliases)
|
|
end
|
|
|
|
class StrictLoadingScope # :nodoc:
|
|
def self.empty_scope?
|
|
true
|
|
end
|
|
|
|
def self.strict_loading_value
|
|
true
|
|
end
|
|
end
|
|
|
|
def preload_associations(records) # :nodoc:
|
|
preload = preload_values
|
|
preload += includes_values unless eager_loading?
|
|
preloader = nil
|
|
scope = strict_loading_value ? StrictLoadingScope : nil
|
|
preload.each do |associations|
|
|
preloader ||= build_preloader
|
|
preloader.preload records, associations, scope
|
|
end
|
|
end
|
|
|
|
protected
|
|
def load_records(records)
|
|
@records = records.freeze
|
|
@loaded = true
|
|
end
|
|
|
|
def null_relation? # :nodoc:
|
|
is_a?(NullRelation)
|
|
end
|
|
|
|
private
|
|
def already_in_scope?
|
|
@delegate_to_klass && klass.current_scope(true)
|
|
end
|
|
|
|
def current_scope_restoring_block(&block)
|
|
current_scope = klass.current_scope(true)
|
|
-> record do
|
|
klass.current_scope = current_scope
|
|
yield record if block_given?
|
|
end
|
|
end
|
|
|
|
def _new(attributes, &block)
|
|
klass.new(attributes, &block)
|
|
end
|
|
|
|
def _create(attributes, &block)
|
|
klass.create(attributes, &block)
|
|
end
|
|
|
|
def _create!(attributes, &block)
|
|
klass.create!(attributes, &block)
|
|
end
|
|
|
|
def _scoping(scope)
|
|
previous, klass.current_scope = klass.current_scope(true), scope
|
|
yield
|
|
ensure
|
|
klass.current_scope = previous
|
|
end
|
|
|
|
def _substitute_values(values)
|
|
values.map do |name, value|
|
|
attr = table[name]
|
|
unless Arel.arel_node?(value)
|
|
type = klass.type_for_attribute(attr.name)
|
|
value = predicate_builder.build_bind_attribute(attr.name, type.cast(value))
|
|
end
|
|
[attr, value]
|
|
end
|
|
end
|
|
|
|
def _increment_attribute(attribute, value = 1)
|
|
bind = predicate_builder.build_bind_attribute(attribute.name, value.abs)
|
|
expr = table.coalesce(Arel::Nodes::UnqualifiedColumn.new(attribute), 0)
|
|
expr = value < 0 ? expr - bind : expr + bind
|
|
expr.expr
|
|
end
|
|
|
|
def exec_queries(&block)
|
|
skip_query_cache_if_necessary do
|
|
records =
|
|
if where_clause.contradiction?
|
|
[]
|
|
elsif eager_loading?
|
|
apply_join_dependency do |relation, join_dependency|
|
|
if relation.null_relation?
|
|
[]
|
|
else
|
|
relation = join_dependency.apply_column_aliases(relation)
|
|
rows = connection.select_all(relation.arel, "SQL")
|
|
join_dependency.instantiate(rows, strict_loading_value, &block)
|
|
end.freeze
|
|
end
|
|
else
|
|
klass.find_by_sql(arel, &block).freeze
|
|
end
|
|
|
|
preload_associations(records) unless skip_preloading_value
|
|
|
|
records.each(&:readonly!) if readonly_value
|
|
records.each(&:strict_loading!) if strict_loading_value
|
|
|
|
records
|
|
end
|
|
end
|
|
|
|
def skip_query_cache_if_necessary
|
|
if skip_query_cache_value
|
|
uncached do
|
|
yield
|
|
end
|
|
else
|
|
yield
|
|
end
|
|
end
|
|
|
|
def build_preloader
|
|
ActiveRecord::Associations::Preloader.new
|
|
end
|
|
|
|
def references_eager_loaded_tables?
|
|
joined_tables = build_joins([]).flat_map do |join|
|
|
if join.is_a?(Arel::Nodes::StringJoin)
|
|
tables_in_string(join.left)
|
|
else
|
|
join.left.name
|
|
end
|
|
end
|
|
|
|
joined_tables << table.name
|
|
|
|
# always convert table names to downcase as in Oracle quoted table names are in uppercase
|
|
joined_tables.map!(&:downcase)
|
|
|
|
!(references_values.map(&:to_s) - joined_tables).empty?
|
|
end
|
|
|
|
def tables_in_string(string)
|
|
return [] if string.blank?
|
|
# always convert table names to downcase as in Oracle quoted table names are in uppercase
|
|
# ignore raw_sql_ that is used by Oracle adapter as alias for limit/offset subqueries
|
|
string.scan(/[a-zA-Z_][.\w]+(?=.?\.)/).map!(&:downcase) - ["raw_sql_"]
|
|
end
|
|
end
|
|
end
|